1. Field of the Invention
The present invention relates generally to optoelectronics and more specifically to methods and apparatus for detecting and processing electrical and optical signals.
2. Discussion of Related Art
Corresponding methods and apparatuses are known for example as “PMD elements” from German patent application No 196 35 932.5 or corresponding international patent application WO 98/10255 and DE 198 21 974.1 and corresponding international patent application WO 99/60629.
The state of the art in regard to that inherent pre-processing of optical signal waves is described for example in “Handbook of Computer Vision and Applications”, Volume 1, Sensors and Imaging, edited by Jähne et al., Academic Press, on pages 463ff and also in dozens of publications relating to uses as laser radar, 3D cameras and OE interfaces for communication, for example on the homepage of the Institut für Nachrichtenverarbeitung of the University of Siegen.
That known photomixing detector (PMD) delivers a push-pull multiplication and correlation of the optical signal wave with an electrical push-pull signal and achieves a high level of noise and background light suppression and also a substantial simplification of and improvement in time measurement procedures. The known PMD and the methods used therewith are however relatively inflexible and have no time selection, no inherently switchable zero condition of the output signal and no analog or digital interlinking of a plurality of electrical and optical input signals. In particular it is not possible with that known method and the known PMD to mix and link together different optical signals.
The broad spectrum of electromagnetic and in particular optical technologies and methods of acquiring, processing and transmitting items of information together with the microelectronic and microoptical technologies has a key function in research, development and production and increasing significance in international commercial competition. Therefore an outstanding part is played by direct processing and interlinking of radiation signals—in particular optical signals—with electrical signals, for example optoelectronic (OE) interface components between optical and electrical technologies and systems, the OE transducers as receivers and the EO transducers as transmitters (for example laser diodes), but also optical signals with each other.